Electrically heated stylus for transferring a printing medium

ABSTRACT

A hand manipulated electrically heated stylus tool for transferring insignia to an article from a ribbon or sheet having a coating on one face thereof subject to release and transfer to an article to be printed operates on a 115 volt power supply without use of a voltage reducing transformer or temperature control means. The tool includes an aluminum stylus having a first portion enclosed in a low thermal conductivity support carried at the end of a handle and a second portion projecting from the support to terminate in a work contacting tip. The entire outer surface of the stylus is anodized to form a hard wear resistant electrically insulative layer thereon. A heating element formed from electrically insulated resistance wire is coiled about the first portion of the stylus with the insulation thereon abutting the anodized layer. The arrangement is such that the anodized layer acts as a back-up insulation between the heating element and stylus to prevent short circuiting of the heating element should the insulation on the resistance wire fail. Additionally, in the further event of the breakdown of the anodized layer about the first portion of the stylus, the operator is protected by reason of the electrical insulation afforded by the intact anodized layer covering the exposed second portion of the stylus.

United States Patent 119'] Veach 4] ELECTRICALLY HEATED STYLUS FOR TRANSFERRING A PRINTING MEDIUM [76] Inventor: Carlos W. Veach, 8921 Ashcroft Ave., Los Angeles, Calif. 90048 [22] Filed: Nov. 15, 1971 [21] Appl. No.: 198,516

[52] US. Cl 219/237, 1 17/37, 219/533, 219/542, 219/548, 228/54, 338/302, 346/76 [51] Int. Cl. 1105b 3/00 [58] Field of Search... 219/221, 227, 229, 236-241, 219/533, 548, 542; 346/76 R; 228/51-55; 338/30l 303; 117/37 R [56] 1. References Cited [451 May 14, 1974 [57] ABSTRACT A hand manipulated electrically heated stylus tool for transferring insignia to an article from a ribbon or sheet having a coating on one face thereof subject to release and transfer to an article to be printed operates on a 1 15 volt power supply without use of a voltage reducing transformer or temperature control means. The tool includes an aluminum stylus having a first portion enclosed in a low thermal conductivity support carried at the end of a handle and a second portion projecting from the support to terminate in a work contacting tip. The entire outer surface of the stylus is anodized to form a hard wear resistant electrically insulative layer thereon. A heating element formed from'electrically insulated resistance wire is coiled about the first portion of the stylus with the insulation thereon abutting the anodized layer. The arrangement is such that the anodized layer acts as a back-up insulation between the heating element and stylus to prevent short circuiting of the heating element should the insulation on the resistance wire fail. Additionally,'in the further event of the breakdown of the anodized layer about the first portion of the stylus, the operator is protected by reason of the electrical insulation afforded by the intact anodized layer covering the exposed second portion of the stylus.

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CARLOS w. VEACH VICTOR c. MULLER ATTORNEY 1 d ELEC'TRICALLY HEATED STYlLUS FOR TRANSFERRING A PRINTING MEDIUM BACKGOUND OF THE INVENTION In the art of printing identification and other insignia it is conventional practice to impress the insignia onto an article by heated type which engages a ribbon or sheet of material having a coating on one side thereof which releases from its backing member under heat and pressure, thus transferring insignia, corresponding to the type, onto the surface of an article which may be leather, paper, photo film, and a myriad of other articles. Such type may be an alphabet, numbers, and various characters like those normally. employed on the striking bars of a typewriter. As will be apparent, however, such apparatus, while satisfactory, is limited in application to the available type characters employed with the apparatus.

Many occasions arise in which it is desired to employ this printing process for impressing an article with other insignia, which may vary between wide limits. Thus, it may be desired to apply a personal signature to the article which, as will be apparent, is possible only by a freehand method of forming same.

Similarly, special characters or insignia, not normally employed by fixed type, may be desired, the formation of which are subjectonly to freehand formation. A picture, character, or any other representation by lines not possible with fixed type are other examples which would thus enlarge the printing possibilities of this type of printing and enable an operator to print anything which corresponds to his freehand execution thereof.

The formation of freehand insignia by the process referred to, as distinguished from fixed type formation thereof presents certain difficulties in that the fixed type systems are under accurate control of temperature to effect the desired transfer of the printing, which controls are not easily applicable to freehand apparatus for attaining similar results and particularly due to spacial limitations, economics of manufacture and others. Thus, the heat input energy to the stylus should be substantially in balance with its heat loss to retain the stylus at substantially constant temperature, a criterion for its successful operation and this, preferably without use of any temperature control device. This presents a difficult problem inheat conduction and insulation when it is considered that the temperature limits are between something of the order of 200 to 400 Fahrenheit.

Another problem resides in safeguarding the operator against electrical shocks in the event of insulation breakdown and attendant short circuits. This is particularly important to meet underwriter approval, the standards of which areparticularly high in any hand held device operating at relatively high voltage,such as 1 V.

SUMMARY'OF THE INVENTION The present invention is characterized by the provision of a freehand manipulated stylus which may form insignia on an article, transferred from a coating on a sheet or ribbon, to the article. Its energy heat input and energy loss output are so related that its stylus may be maintained within limits of operable temperatures without the use of temperature control devices, such as thermostats or the like. It is further characterized by an insulated heater coil surrounding a metallic stylus with a back-up insulation between the heater coil insulation and stylus. In the event of breakdown of the heater coil insulation the back-up insulation prevents a short circuit between convolutions of the heater coil; additionally, in the further event of break-down of the back-up insulation, the exposed portion of the stylus remains insulated from the operator, thus confining the short circuit to a locus where the operator remains protected.

In accordance with the concepts as briefly set forth above, one of the objects of this invention is to provide a hand-manipulated heated stylus for transferring material, such as metal or a pigment from a coated ribbon or sheet onto an article.

Another object is to maintain the stylus within its operable temperatures by substantially balancing the heat applied to the stylus with the lost heat therefrom and without the use of thermostatic controls.

Another object is to attain maximum heat conduction to the stylus with insulators best selected for their heat conductive and electrical insulating characteris tics.

Another object is to provide back-up insulation for an insulated heater coil which becomes operative in event of failure of the heater coil insulation to thus prevent a short circuit between heater coil convolutions.

Another object is to provide insulation between a stylus and an operator in the event of break-down of the back-up insulation.

Still further objects, advantages, and salient features will become more apparent from the detailed description to follow, the appended claims, and accompanying drawing, to now be briefly described.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an approximately to scale side elevation of the subject of the invention, a portion being broken away.

FIG. 2 is an enlarged section taken on line 2-2, FIG. 1, a portion being omitted;

FIG. 3 is an enlarged section taken on line 33, FIG.

FIG. 4 is an enlarged section taken on line 4-4, FIG. 3; and

FIG. 5 is a section through a coated sheet of material and an article to which printing is being transferred.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, and first to FIG. 1, the subject of the invention comprises briefly, a tube 10 with a surrounding sheath l2 closed at one end by a cap 14 and at its other end by a frusto-conical closure or plug 16 which supports a stylus 18.

As best shown in FIGS. 2 to 4, stylus 18 is formed of round aluminum rod with a rounded tip 20, the stylus being anodized to form an electrical insulating coating 22 thereon. Resistance wire 24, having insulation 26 thereon, is coiled around the rod in adjacent abutting coils, the ends of which are affixed to leads 28. The assembly just described is then suitably supported in a mold (not shown) and potted with liquid hardenable material which forms nose 16 previously referred to. As will be apparent, each coil is insulated from its adjacent coil by two thicknesses of insulation and is insulated from the aluminum rod by one thickness of surrounding insulation and also by the thickness of the anodizing insulation. Thus, in the event of a break-down of the insulation where it engages the anodizing, it still remains insulated from the stylus and prevents a short circuit between coils and through the stylus. Further, in the remote event of break-down of the anodizing insulation beneath the coils, any short circuit therebetween will be through the aluminum rod and within nose 16. Since the exposed portion of the stylus is also anodized, and hence electrically insulated, the operator is protected against any possible electrical shock.

FIG. 5 illustrates the manner of use of the device in I which stylus 18 is moved across the surface of the on one face thereof and the printing material 34 to be transferred to an article 36. As will be understood, application of heat and pressure to ball end 20 transfers heat to the release agent and impresses material 34 into contact with article 36 along a line below the movement of end 20. Material 34 maybe a metal, a metallic compound or non-metallic pigment, which is conventional and chosen in accordance with desired color. As will be apparent, further, the transfer sheet, which may be inribbon orother sheet form comprises no part of the invention per se.

Tube is preferably of metal, such as aluminum, and sheath 12 is of heat insulating material, such as paper. Cap 14 may be formed of moulded plastic, and retained in position by cement. Nose 16 is preferably formed from finely comminuted ceramic particles mixed with an air hardenable liquid vehicle, such as epoxy cement. The nose may be secured in tube 10 in any suitable manner, such as by cement. A thickness of anodizing of approximately 0.002 inch has been found to provide excellent electrical insulation and also adequate heat conduction to the stylus. While some heat conduction from the heating coil occurs at its larger diameter and to tube 10, the major portion occurs at the frusto-conical exposed portion of the nose and to ambient air. As will be apparent, since the nose is of decreasing diameter, the temperature gradient at its smallest diameter is-greater than at its largest diameter. The resistance wire is of a diameter of the order of 0.00l inch with enamel insulation thereon of a thickness of the order of 0.0002 inch. Wire formed principally of Cu-Ni-Cr, such as Nichrome, having resistance of 300 800 ohms per lineal foot has been found to give satisfactory results. The insulation on the resistance wire should preferably have about a 500F breakdown temperature. The device is designed to operate on voltage of the order of ll5V Ac. However, if desired, a diode may be incorporated in the handle to render the same heating coil operable on 220V Ac. As will be apparent, since the coils are not coupled with magnetic material, impedance is negligible and hence total resistance is substantially the same operated on Ac or Dc. 4

I claim:

l. A device for transferring a printing medium, forming a coating on one face of a sheet of material, and subject to release therefrom upon movement of a heated stylus along the opposite face of the sheet in a desired path, while the medium is in contact with an article to be printed, comprising;

a. a hollow handle adapted to be grasped in the hand of an operator for freehand movement in a path corresponding to the configuration of insignia to be printed,

b. said handle having a stylus supporting member at one end thereof formed of electrical insulating material of relatively low heat conductivity,

c. an aluminum stylus having a first portion disposed within said member and a second portion projecting therefrom, terminating in a free end adapted to be moved along said opposite face,

d. said stylus having an anodized coating thereon and coextensive therewith, said coating being relatively hard to thereby resist wear on said free end and also forming an insulator layer around the stylus.

e. a continuous insulated wire of relatively high electrical resistance wound around said first portion in a plurality of abutting coils, the insulation on the coils also abutting the anodized coating, said coils forming a heating element for supplying heat to the stylus through the anodized coating, and

f. electrical conductors within said handle connecting ends of the heating element with an electrical source,

g. the construction and arrangement being such that adjacent coils are electrically insulated from each other by at least two thicknesses of wire insulation and each coil is electrically insulated from the stylus by its surrounding insulation and by the anodized coating whereby in the event of breakdown of the insulation surrounding the coils they remain insulated from the stylus because of said anodized coating, and in the further event of breakdown of the anodized coating on said first portion, producing a short circuit between coils through the stylus, the projecting second portion of the stylus remains electrically insulated from the operator because of the anodized coating thereon.

2. A device in accordance with claim 1 wherein said heating element is of such resistance to provide heat to maintain said free end between approximately 200 to 400 fahrenheit.

3. A device in accordance with claim 1 wherein said stylus and heating coil are potted in said supporting member, the material of said supporting member being a mixture of ceramic and liquid resin subject to hardening after being cast to desired shape.

4. A device in accordance with claim 3 wherein said supporting member is generally frusto-conical and said stylus is disposed axially thereof, whereby the maximum radial temperature gradient across said member is at the smallest cross section thereof. 

1. A device for transferring a printing medium, forming a coating on one face of a sheet of material, and subject to release therefrom upon movement of a heated stylus along the opposite face of the sheet in a desired path, while the medium is in contact with an article to be printed, comprising; a. a hollow handle adapted to be grasped in the hand of an operator for freehand movement in a path corresponding to the configuration of insignia to be printed, b. Said handle having a stylus supporting member at one end thereof formed of electrical insulating material of relatively low heat conductivity, c. an aluminum stylus having a first portion disposed within said member and a second portion projecting therefrom, terminating in a free end adapted to be moved along said opposite face, d. said stylus having an anodized coating thereon and coextensive therewith, said coating being relatively hard to thereby resist wear on said free end and also forming an insulator layer around the stylus, e. a continuous insulated wire of relatively high electrical resistance wound around said first portion in a plurality of abutting coils, the insulation on the coils also abutting the anodized coating, said coils forming a heating element for supplying heat to the stylus through the anodized coating, and f. electrical conductors within said handle connecting ends of the heating element with an electrical source, g. the construction and arrangement being such that adjacent coils are electrically insulated from each other by at least two thicknesses of wire insulation and each coil is electrically insulated from the stylus by its surrounding insulation and by the anodized coating whereby in the event of breakdown of the insulation surrounding the coils they remain insulated from the stylus because of said anodized coating, and in the further event of breakdown of the anodized coating on said first portion, producing a short circuit between coils through the stylus, the projecting second portion of the stylus remains electrically insulated from the operator because of the anodized coating thereon.
 2. A device in accordance with claim 1 wherein said heating element is of such resistance to provide heat to maintain said free end between approximately 200* to 400* fahrenheit.
 3. A device in accordance with claim 1 wherein said stylus and heating coil are potted in said supporting member, the material of said supporting member being a mixture of ceramic and liquid resin subject to hardening after being cast to desired shape.
 4. A device in accordance with claim 3 wherein said supporting member is generally frusto-conical and said stylus is disposed axially thereof, whereby the maximum radial temperature gradient across said member is at the smallest cross section thereof. 